Environmentalists may applaud corporate efforts to sell fewer polluting and poisonous goods and services. But some consumer watchdogs warn that the proliferation of green claims will confuse or mislead shoppers, and prefer that companies agree on industry-wide standards.

This CNET guide to green labels covers popular, third-party markings on electronics and other products. Their logos represent pooled efforts by experts not on the payroll of companies selling the labeled products, such as scientists, nonprofit groups, designers, and government officials.

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